PROSPECTING FOR GROUND WATER CONTAMINATION FROM
ON-SITE WASTEWATER SYSTEMS IN NEW MEXICO
Bruce Thomson1, Gwinn Hall2, John Stormont1, Jeff Peterson3, Adrian Hanson4
ABSTRACT:
While on-site wastewater treatment and disposal systems are frequently blamed for
groundwater contamination, few hydrogeologic investigations have actually been
conducted to quantify their impact. Fewer still have been done in arid environments that
are characterized by high evaporation, low rainfall, porous soils, and large depths to
ground water. This paper describes a field investigation to measure the impacts of high
densities of septic tank systems on ground water quality near Albuquerque, NM.
Surprisingly little contamination was found including very low concentrations of nitrate.
One mechanism for nitrogen removal may be subsurface nitrification-denitrification in
deep unsaturated soils. The implications for development densities in unsewered
communities will be discussed.
1
Dept. of Civil Engineering, University of New Mexico, Albuquerque, NM 87131
Daniel B. Stephens & Associates, Albuquerque, NM 87110
3
Dept. of Public Works, Bernalillo County, Albuquerque, NM 87102
4
Dept. of Civil, Agricultural & Geological Engineering, New Mexico State University, Las Cruces, NM
88003
2